In general, air cleaner arrangements are utilized to filter combustion air intake streams for various engine applications, including for example, for vehicles and stationary engines. One typical approach has been to utilize a primary element to remove the bulk of particulates, and a secondary element, downstream of the primary element. The secondary element is used to catch larger particulate matter that may have, for one reason or another, made it past the primary filter element. For example, if the primary filter element fails, or becomes unsealed, the secondary element is oriented to protect the engine from any large particles and debris.
Further, in many types of systems, the primary filter element becomes loaded with particulates, and needs to be replaced. During the replacement process, particulate material and debris can fall off of the primary element and into the air intake duct of the engine. It is desirable to have a secondary element positioned to catch any of the particulates and debris that fall off of the primary element when it is being serviced and replaced.
A variety of air filter or gas filter arrangements have been developed for particulate removal. In general, however, continued improvements are sought.